Footwear with dynamic modulation

ABSTRACT

The present invention is directed toward an article of footwear including a sole structure and an upper. The upper includes an area of dynamic modulation. Specifically, the footwear upper defines a discrete band whose elasticity and/or dimension is altered in the presence of a specified temperature. In an embodiment, the footwear upper includes a shape memory polymer operable to alter the circumference of the foot cavity and/or alter the expansion properties of the upper  105.  By way of example, the discrete band may be positioned within the collar and/or along the instep of the upper. With this configuration, the footwear defines support areas operable to provide the wearer with improved fit and/or recovery

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a nonprovisional of U.S. provisional application no. 62/241,855, filed 15 Oct. 2015 and entitled “Footwear with Dynamic Modulation,” the disclosure of which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present application is directed toward an article of footwear and, in particular, to an article of footwear including an upper capable of dynamic modulation.

BACKGROUND OF THE INVENTION

Footwear is designed for comfort and performance. Accordingly, footwear is constructed from a material or a combination of materials selected to provide desired attributes. While fit is important to the wearer, this must be balanced against the ease of donning and doffing the shoe. Conventional footwear does not alter its physical structure to accommodate for a change in conditions. For example, an upper including perforations to permit fluid flow is capable of the same level of fluid passage regardless of whether the environment inside of or outside of the shoe is at ambient temperature or at an elevated temperature (i.e., at a measured temperature above ambient). By way of further example, once donned, the fit of the footwear remains consistent throughout its use, being controlled by a lacing system attached to the upper.

Thus, it would be desirable to provide a shoe that reacts to the conditions of its internal microclimate and/or exterior environmental conditions to alter one or more characteristics of the shoe, such as fit.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed toward an article of footwear including a sole structure and an upper. The upper includes one or more areas of dynamic modulation. The area of dynamic modulation includes a shape memory polymer configured to alter its structure when a predetermined temperature is achieved within or without the cavity. In an embodiment, the shape memory polymer contracts to reduce a dimension of the foot cavity and/or apply pressure to the foot of the wearer. In another embodiment, the resiliency of the shape memory polymer lessens to alter the stretch characteristics of the upper. With this configuration, the article of footwear is dynamic, changing its fit and/or performance characteristics depending on surrounding conditions.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 illustrates a perspective view of an article of footwear in accordance with an embodiment of the invention.

FIG. 2 illustrates a side view in elevation of the article of footwear of FIG. 1 (shown in perspective).

FIG. 3 illustrates a side view in elevation of an article of footwear in accordance with another embodiment of the invention, showing a high top configuration.

FIG. 4 illustrates a perspective view of an article of footwear in accordance with an embodiment of the invention.

Like numbers have been utilized to indicate like components throughout the figures.

DETAILED DESCRIPTION OF THE INVENTION

As shown in FIGS. 1 and 2, the article of footwear 100 includes an upper 105 and a sole structure 110 that cooperate to define a forefoot region, a midfoot region, and a hindfoot region, as well as a medial side and a lateral side. The forefoot region generally aligns with the ball and toes of the foot, the midfoot region generally aligns with the arch and instep areas of the foot, and the hindfoot region generally aligns with the heel and ankle areas of the foot. Additionally, the medial side is oriented along the medial (big toe) side of the foot, while the lateral side is oriented along the lateral (little toe) side of the foot.

The upper 105 includes an outer shell 115 and a collar 130 that provides access to an internal foot cavity 125. An inner, dynamic textile 120 is housed within the shell 115, being disposed on the shell interior surface at selected locations throughout the foot cavity 125. In an embodiment, the dynamic textile 120 is provided as a sock liner coupled (e.g., connected) to the interior surface of the outer shell 115. In another embodiment, the dynamic textile 120 forms a bootie suspended within the foot cavity 125 (i.e., the bootie moves relative to the outer shell 115).

The dynamic textile 120 is a woven, knitted, or nonwoven textile structure including staple fibers and/or filaments (monofiliament or multifilament), including yarns made from natural or synthetic fibers. In addition, the dynamic textile 120 (i.e., the entire textile or selected areas thereof) includes dynamic material adapted to modulate when the material reaches a predetermined temperature. In general, the predetermined temperature is an elevated temperature, i.e., a temperature above ambient temperature. The elevated temperature may be caused by the internal conditions of the foot cavity 125 (e.g., heat emanating from the user), or by the heat transferred to the dynamic textile layer 120 via the outer shell 115 (e.g., heat of friction caused by the shell contacting surfaces during use).

In an embodiment, the dynamic textile 120 is disposed at selected locations along the upper 105. By way of example, the dynamic textile layer 120 includes a first dynamic region 135A disposed along the collar 130 (e.g., proximate the malleolus) of the upper 105, and a second dynamic region 135B disposed over the instep of the upper (e.g., the second dynamic region is configured to align with the area between the calcaneous and metatarsis portions of the foot). The regions 135A, 135B may be separated from each other or may be connected via a bridge 140 (FIG. 2) of dynamic material extending from the first region 135A to the second region 135B.

The dynamic material of the dynamic textile 120 is a polymer operable to repeatedly respond in a predictable manner when a consistent stimulus is applied. The dynamic material provides a reversible response to the changes in the surrounding environment by changing physical properties, geometry, and/or mechanical properties upon exposure to stimuli (e.g., heat, moisture, electricity, light, magnetism, and/or strain). Dynamic materials include shape memory alloys (SMAs), shape memory ceramics (SMCs), and shape memory polymers (SMPs). In a preferred embodiment, SMPs are utilized. SMAs are heavier and possess poor hand when compared to SMPs. SMPs, moreover, possess high shape recovery, are easily deformed, possess high strain capabilities, and have mechanical properties that may be tailored for a desired end use.

Dynamic materials such as SMPs possess the ability of recovering an original shape or converting from a first shape to a second shape. In other words, SMPs having one-way or two-way shape memory effects may be utilized. In a one-way effect transition, the SMPs switch from a deformed shape to an original shape upon the application of a stimulus. Two-way effect transition occurs when the SMP switches back and forth from one specified shape to another specified shape (rather than any shape to one shape). This is accomplished by adding material with a higher elastic modulus where the crystalline network acts as a switch. The reversible shape shrinkage and the higher elastic material network (added into the matrix of the other material) acts as a spring and a pushing force to provide shape expansion during cooling.

In an embodiment, a thermo-responsive shape memory polymer is utilized. The chemical structure of an SMP includes crosslinks that define its shape above a predetermined temperature, as well as switchable segments that generate a change in shape at a temperature falling below the predetermined temperature. This predetermined temperature is called the switching or transition temperature. By way of example, the SMP is a copolymer including hard and soft segments. By way of specific example, a shape memory polyurethane (SMPU) is utilized.

The switching temperature of the SMP is selected to fall in a window at or above ambient temperature. The switching temperature is selected to fall within typical conditions present within a foot cavity during use. In an embodiment, the switching temperature falls in a range of from about 20° C. to about 37° C., more preferably from about 25° C. to about 33° C. and/or from about 33° C. to about 37° C. Configuring the contraction effect to occur in this range—or a first transition to occur during a the lower sub-range and a second transition to occurs in the higher sub-range—would provide for activation of the upper shortly after the shoe is donned and/or for a first activation after the shoe is donned and a second during peak athletic temperatures experienced during use (e.g., gameplay or exercise).

The heat applied to the SMP includes heat released from the body and/or heat generated by movement and friction within the shoe. Thus, the activation of the SMP could be heat from interaction between the outside of the shoe and exterior object (e.g., heat of friction caused by the shoe contacting the playing field (e.g., turf grass), or heat existing in the internal environment of the shoe).

The SMP may be incorporated into the dynamic textile 120 as a strand, may be applied as a film (membrane), or may be applied as a coating. The term strand includes a single fiber, filament, or monofilament, as well as an ordered assemblage of textile fibers having a high ratio of length to diameter and normally used as a unit (e.g., slivers, roving, single yarns, plies yarns, cords, braids, ropes, etc.). In a preferred embodiment, a strand is yarn (a continuous strand of textile fibers, filaments, or material in a form suitable for knitting, weaving, or otherwise intertwining to form a textile fabric). A yarn may include a number of fibers twisted together (spun yarn); a number of filaments laid together without twist (a zero-twist yarn); a number of filaments laid together with a degree of twist; and a single filament with or without twist (a monofilament).

An exemplary SMP strand is discussed in US Published Patent Application No. 2009/0093606, the disclosure of which is incorporated by reference in its entirety. Another exemplary strand is a PEG-based polyurethane hollow fiber whose internal channel diameter changes upon heating above the switching temperature.

The dynamic region 135A, 135B of the upper 105 may be formed solely of the SMP strand (incorporated into the textile), or may be blended with other strands. By way of specific example example, DIAPLEX may be formed into a strand and incorporated into the upper (e.g., as a yarn). Other, non-SMP strands include natural strands and/or synthetic strands formed of one or more types of polymers. Examples of non-SMP strands include synthetic materials such as polyester, nylon, polypropylene, polyethylene, acrylics, acetate, and polyacrylonitrile, as well as natural materials such as cellulosic fibers (e.g., cotton, bamboo) and protein fibers (e.g., wool, silk, and soybean).

Alternatively, the dynamic region may be formed by coating a textile (formed of non-SMP strands) with a formulation that generates the dynamic effect within the textile. An exemplary film or coating is commercially available under the trade name DIAPLEX (available from SMP Technologies Inc., Tokyo, Japan). The coating may be applied to a textile formed of the non-SMP strands discussed above. The coating thickness may be selected based on the desired level modulation in the fabric (e.g., thicker coating generates a higher degree of modulation than thinner coatings).

In still another embodiment, the dynamic region 135A, 135B includes both strands (forming the textile) and a coating or film applied to the textile.

With the above configuration, the article of footwear adapts to the environment of the foot cavity 125 to selectively activate the dynamic regions 135A, 135B and alter the performance characteristics of the upper 105. For example, the shape memory polymer may be configured to change its dimensions above the transition temperature. Specifically, the SMP may contract (lessen its dimensions) when the switching temperature is reached. Upon contraction, the circumference (diameter) of the foot cavity 125 or the opening (diameter) of the collar 130 becomes smaller, with the dynamic textile 120 being drawn toward the foot of the wearer.

With this configuration, the fit or the compression properties of the upper 105 may be selectively modified. As noted above, the SMP may be trained to react in a particular manner when heat is applied. Accordingly, the SMP may contract to a specified degree. At lower levels of contraction, the dynamic textile 120 is effectively drawn toward the foot, contouring to the foot's shape. This, in turn, improves the overall fit of the upper.

At higher levels of contraction, moreover, the circumference is altered sufficiently to apply compression to selected foot muscles. Compression is believed to provide performance enhancement and to reduce injury, particularly during exercises provoking high blood lactate concentrations or explosive-based movements. It is known that compression garments may promote blood lactate removal and therefore enhance recovery following strenuous exercise. It is believed, moreover, that the use of compression garments during recovery periods may reduce the symptoms associated with delayed onset muscle soreness. Accordingly, by increasing the pressure applied to the foot, the shoe can provide recovery benefits to the wearer.

The manner in which the contraction of the SMP is determined is not particularly limited. By way of example, the loop density per centimeter squared of shape memory fabric may be utilized. In addition, the length of course-wise direction of shape memory fabric or the course per cm may be utilized.

When application of pressure is the desired metric, the range of applied compression may be from about 1 mm Hg to about 40 mm Hg.

In another embodiment, the resiliency of the dynamic textile 120 is altered when the switching temperature is reached. Although a shoe should be easy to place on the foot, once in the foot, the wearer typically desires a secure, locked in feeling. By configuring the shape memory polymer to switch from a state having a higher modulus of elasticity to a state having a lower modulus of elasticity, the upper 105 can snugly hold the foot with in the foot cavity 125, minimizing movement permitted by the stretch of the upper.

The sole structure 110 may be formed of a single material or may be formed of a plurality of materials. In example embodiments in which the sole structure includes a midsole and an outsole, the midsole may be formed of one or more materials including, without limitation, ethylene vinyl acetate (EVA), an EVA blended with one or more of an EVA modifier, a polyolefin block copolymer, and a triblock copolymer, and a polyether block amide (e.g., a PEBAX® material). The outsole may be formed of one or more materials including, without limitation, elastomers (e.g., thermoplastic polyurethane), siloxanes, natural rubber, and synthetic rubber.

FIG. 3 illustrates an article of footwear in accordance with another embodiment of the invention. As with the above embodiment, the article of footwear 300 includes an upper 305 and a sole structure 310. The article of footwear, however, is configures as a “high top” shoe, including an elongated collar 315 defining opening 320. The dynamic region 325 of the shoe is configured as a unitary cage extending across the instep of the foot and around the collar opening 320. With this configuration, the elongated collar 315 may be configured to compress along the ankle of the wearer. Compression not only improves fit and/or recovery, but also generates a locked down effect with the user, stabilizing the foot and ankle, lessening the chances of inversion/eversion.

FIG. 4 illustrates an article of footwear in accordance with another embodiment of the invention. As shown, in this embodiment, the article of footwear 400 is a recovery slide with a strap 405 extending over the foot and a generally level sole structure 410. The SMP may form the strap 405. Accordingly, as the user wears the slides, the strap may contract, hugging the foot and applying increased pressure thereto.

While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. For example, the dynamic textile layer 120 may be formed by any suitable method, including knitting and weaving, and may be a nonwoven textile. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. It is to be understood that terms such as “top,” “bottom,” “front,” “rear,” “side,” “height,” “length,” “width,” “upper,” “lower,” “interior,” “exterior,” “medial,” “lateral,” and the like as may be used herein, merely describe points of reference and do not limit the present invention to any particular orientation or configuration. 

1-4. (canceled)
 5. An article of footwear comprising: an upper comprising an outer shell and an inner textile liner coupled to the shell such that it defines at least a portion of a foot cavity configured to receive a foot, the inner liner being formed of dynamic material adapted to possess a first physical property at a first temperature and a second physical property at a second temperature, wherein a change from the first temperature to a second temperature alters a physical characteristic of the upper.
 6. The article of footwear according to claim 5, wherein the dynamic material is selected from the group consisting of shape memory alloys, shape memory ceramics, and shape memory polymers.
 7. The article of footwear according to claim 6, wherein the dynamic material is shape memory polymer.
 8. The article of footwear according to claim 7, wherein the shape memory polymer is a polyurethane shape memory polymer.
 9. The article of footwear of claim 8, wherein: the foot cavity defines a cross-sectional dimension; and the physical characteristic is the foot cavity cross-sectional dimension.
 10. The article of footwear according to claim 1, wherein dynamic material is disposed at selected locations within the inner textile liner.
 11. The article of footwear according to claim 11, wherein: the upper includes: a collar region configured to align with a malleolus of a foot, and an instep region configured to align with the area between calcaneous and metatarsis portions of the foot; the collar region is formed of dynamic material to define a first dynamic region; and the instep region is formed of dynamic material to define a second dynamic region.
 12. The article of footwear according to claim 11, wherein the first dynamic region is oriented in spaced relation from the second dynamic region.
 13. The article of footwear according to claim 12, wherein a bridge dynamic material extends from the collar region to the instep region.
 14. The article of footwear according to claim 13, wherein: the shape memory polymer possesses a switching temperature; and the switching temperature of the shape memory polymer falls within a range of from about 20° C. to about 37° C.
 15. The article of footwear according to claim 14, wherein the switching temperature is from about 25° C. to about 33° C. and/or from about 33° C. to about 37° C.
 16. The article of footwear according to claim 13, wherein the shape memory polymer is strand incorporated into textile.
 17. The article of footwear according to claim 16, wherein the dynamic textile includes the shape memory polymer strand a non-shape-memory-polymer strand.
 18. The article of footwear according to claim 17, wherein the non-shape memory polymer strand strand comprises polyester, nylon, polypropylene, polyethylene, acrylics, and/or cotton. 